1. Field of the Invention
The invention relates to the field of photodynamic therapy and in particular to a vaginal speculum used for intravaginal photodynamic treatment.
2. Description of the Prior Art
Photodynamic therapy of skin tissues is well known. However, there has been no application of photodynamic therapy for the diagnosis and treatment uterine abnormalities. Premalignant changes of vagina, vulva and cervix occur in untold thousands of females annually in the United States. For reasons which are unknown, the number of new cases which have been detected have steadily risen in the last 10 to 15 years. Intraepithelial neoplasia of the genital tract can occur in various locations in the form of vaginal intraepithelial neoplasia, vulvar intraepithelial neoplasia, and cervical intraepithelial neoplasia.
Conventional treatment of unifocal, small, low grade intraepithelial neoplasia of the genital tract is usually performed using a variety of locally tissue destructive techniques, such as CO.sub.2 laser vaporization, cryotherapy, electrocautery, or local excision. In the case of multifocal, large, or high grade intraepithelial neoplasia, more extensive surgical procedures are used, typically skinning vulvectomy, partial vaginectomy or hysterectomy. Radical surgical procedures are deemed necessary not only because of the higher failure rate which has been experienced in the treatment multifocal, large or higher grade intraepithelial neoplasia, when treated with local destruction only, but also particularly in the case of multifocal lesions because of the tendency of those lesions to recur outside of the locally treated area. For this reason, the entire diseased organ must be removed to assure that all microscopic disease is treated. Since the percentage of these lesions that will advance to a frankly malignant state is unknown and may be a minority of instances, indiscriminate destruction or surgical removal of the entire organ is, in fact, a radical and excessive treatment.
Therefore, what is needed is some type of procedure and instrument which can effectively be used in the treatment of vaginal, cervical and vulvar intraepithelial neoplasias without the radical approach of conventional treatments and yet which will be effective.